| 摘要 |
PURPOSE:To directly cool a lens, to eliminate the need for a cooling water tube and to remove deflection from the lens, by pouring assist gas between a total transmission type window in a machining head and a machining lens provided with many through holes and furthermore passing the assist gas through the through holes. CONSTITUTION:A laser beam 2 passes through the total transmission type window 11 and is collected by the machining lens 60, while the assist gas 10 is poured from an assist gas entrance 90 mounted on the machining head 40 into an upper machining head space A. The gas advances continuously to the lower direction and passes through many through holes 61 provided on the machining lens 60 and at the same time directly cools the machining lens 60. The assist gas 10 which has passed through the through holes 61 is blown against the surface of the work 100 through the nozzle 8. Accordingly a cooling water tube need not be fitted in the machining head and the lens can be easily detached. |
